It looked like Royals, who reached the semi-final last season, would be exiting the competition at the first hurdle when the hosts edged in front soon after the interval through Jamie Paterson’s header.

But Matej Vydra levelled things up with his third goal of the season and Hal Robson-Kanu then looked to have booked Reading’s spot in the fourth round when he struck three minutes from time.

Huddersfield had other ideas, however, and after Oliver Norwood was adjudged to have tripped Harry Bunn in the box - Nahki Wells struck from the spot to snatch a replay with just seconds remaining.

It was a remarkable ending to a game which had seen both sides struggle to create anything prior to Paterson’s opener early in the second half.

The Town midfielder ghosted into the box to head home from 12 yards after a ball had been whipped in from the left.

At that point Reading looked to be heading out of the Cup until Vydra grabbed an equaliser totally against the run of play.

The frontman expertly received the ball wide on the left, cut inside his man and let fly with a shot which looped over Town keeper Joe Murphy thanks to a deflection.

There was a large slice of luck about the goal - but that will matter little to Vydra, who will the hope the strike will prove to be a turning point in what has been a frustrating campaign.

The equaliser revitalised the visitors, with the introduction of Lucas Piazon giving them a threat that was severely lacking throughout the opening hour.

And it was the Brazilian who looked to have set up the winner when his clever run into the box ended with Robson-Kanu firing home left-footed with just three minutes remaining.

But Town capped a crazy ending to the contest when they were awarded a penalty with just seconds remaining and Wells made no mistake from the spot to earn his side a replay at Madejski Stadium.